Year	%
2003	21.4
2004	21
2005	21
2006	21.7
2007	21.7
2008	21.6
2009	22
2010	21.9
2011	21.6
2012	22.1
2013	22.3
2014	22.2
2015	22.3
2016	22
2017	22.1
2018	22
2019	22
2020	22.2
2021	21.7